Apparatus for securing lining material to brake shoes



M y 4, 1954 A. WESSTROM ETAL 2,677,408 APPARATUS FOR SECURING LINING MATERIAL TO BRAKE SHOES 14 Sheets-Sheet 1 Filed NOV. 15, 1950 INVENTORS ALFRED WE68TEOM YEM/L I? BuYssE ATTOENEY May 4. 1954 A. WESSTROM ETAL 2,677,408

APPARATUS FOR SECURING LINING MATERIAL T0 BRAKE SHOES Filed Nov. 15, 1950 14 Sheets-Sheet 2 L2 42 Z INVENTORS ALFRED WE$$TEOM BY 574/1. 7? BUYJSE AT TOENE Y May 4, 1954 A. WESSTROM ETAL 2,677,403

APPARATUS FOR SECURING LINING MATERIAL TO BRAKE SHOES Filed Nov. 15, 1950 14 Sheets-Sheet 3 ATTOENE Y May 4, 1954 A. WESSTROM ETAL APPARATUS FOR SECURING LINING MATERIAL T0 BRAKE SHOES l4 Sheets-Sheet 4 Filed Nov. 15, 1950 INVENTORS ALFRED WESSTEOM BY EM/L P Bus 66E ATTOENE Y May 4, 1954 A. WESSTROM ETAL 2,677,408

APPARATUS FOR SECURING LINING MATERIAL T0 BRAKE SHOES Filed Nov. 15, 1950 14 Sheets-Sheet 5 I N V EN TORJ) ALFRED WEssT/POM BYEM/L F. Bums:

Add/m4;

ATTORNE Y May 4, 1954 A. WESSTROM ETAL 2,677,408

APPARATUS FOR SECURING LINING MATERIAL TO BRAKE SHOES Filed NOV. 15, 1950 14 Sheets-Sheet 6 v IN V EN T 0R6 A LFEED W566 TROM BYEM/L P Bums:

AT TOENEY y 4, 1954 A. WESSTROM ETAL 2,677,408

APPARATUS FOR SECURING LINING MATERIAL T0 BRAKE SHOES Filed Nov. 15, 1950 14 Sheets-Sheet 7 INVENTORJ ALF/P50 WEssTEO/v BY EM/L P Bums/5 I AT TOENE Y May 4, 954 A. WESSTH'OM ET AL 2,677,408

APPARATUS FOR SECURING LINING MATERIAL TO BRAKE SHOES Filed Nov. 15, 1950 14 SheetS- -Sheet 8 INVENTORS ALFRED WEssT/20M BY EM/L P Bursa:

Jaw

AI TORNE Y May 4, 1954 A. WESSTROM ETAL 2,677,408

APPARATUS FOR SECURING LINING MATERIAL TO BRAKE SHOES Filed Nov. 15, 1950 14 Sheets-Sheet 1o IN V ENTOR3 A 1. FEED Wsas TEOM BY EM/L. P Bums/5 Maw ATTORNEY May 4, 1954 A. WESSTROM ETAL 2,677,403

APPARATUS FOR SECURING LINING MATERIAL TO BRAKE SHOES Filed Nov. 15, 1950 14 Sheets-Sheet ll IN VEN TORJ ALF/e50 Mass-mom BYEM/L I? Bums:-

ATTORNEY May 4, 1954 A. wEss'rRoM ETAL 2,

APPARATUS FOR SECURING LINING MATERIAL TO BRAKE SHOES Filed Nov. 15, 1950 14 Sheets-Sheet l3 M $t r n J INVENTORS F1 9, E 5 ALF/2E0 WEJSTPOM BY EM/L P B UYJSE MAE/M ATTORNEY May 4, 1954 A. WESSTROM ETAL 2,677,408

APPARATUS FOR SECURING LINING MATERIAL TO BRAKE SHOES Filed Nov. 15, 1950 14 Sheets-Sheet 14- /36 Z Z 9 q 225 w y inn 65 Z6? 70 Z62 lia- INVENTORS AL FEED WEISSTPOM BY [ML B UYSSE A T TOE/VS? Patented May 4, 1954 UN I TED S TATES "$677 ,408

ArrA'irATUsFoitfsEoUR o LiNiNG MATE- RIAL "r BRAKE SHOES Alfred Wess'trom and Emil PrBiiy's'se; South Bend, lnd assignors to Bendix Aviation Corporation, SouthBend, Ind-., acorporation off-Delaware :hifilicafifih Nbv'inbefli 1950, Serial N 0. 195,832

14 Claims. 1

The present invention relates to apparatus useful in bonding brake'lihings w-brake shoes, and particularl to an apparatus adapted to elamp'prake shoe and lining assemblies together under a predetermined pressure in their proper relative positions and carry them through a bond i'ng cycle.

The process generally followed in bonding-a brake shoe and lining assembly together includes the steps of coating the rayin surface of the lining or shoe with a thermosetting adhesive, clamping the lining'and shoe together under a predetermined pressure and heating the assembly until the adhesive has Cured and produced a secure bond. Various devices have been suggested for carrying out these stepsandsome have'been adopted by industry for mass producing bonded brake shoes. The present invention is directed to providing useful improvements inthe mass production of bonded brake shoes and has for its primary object'the provision of an apparatus or inechanismwhioh appreciably increases the rate at which sueh=bonded shoes maybe produced.

It is another object of the present invention to provide a mechanism which maybe operated by a single operator whose only functionis to load the mechanism with-an adhesive-coated lining and brake shoe whereafter themechanism will automatically clamp the shoe and lining together under a predetermined pressure, pass the-shoe assembly through a curving oven, and thereafter dump the bonded shoe assembly into a discharge conveyor, said mechanism then being ready'to accept another shoe and lining assembly from the operator.

It is another object to provide a'bonding fixture adapted tosecurely clamp together, in proper I relative positions and undera predetermined pressure, a brake shoe and lining assembly. It is still another object to provide novel cam actuatin'g means I cooperatively associated with saidfixture to control the latters clamping and uncla-mpi'ng action.

It is still another object to provide an auxiliary pressure device in combination with said fixture and said cam-actuating means-for acting on said fixture insuch a manner as to' securely lodk, under a predetermined pressure, a shoe and liming assembly in place in said fixture.

Still'further objects will become apparent'as the description proceedst In the drawings: v

Figure 1 is a diagrammatic iilustrationof an einiaodimeht of "the present invention:

Figurez is a" man perspective illustrating the lower front and side portins 'of'themechanism Ofthis invention, with the bonding fixtursafid part of tlieeam ra.11-csnsn-uesn removed therefrom; I a

"Figure 3 is ani-llustration siiriilartoFigurefi but showing the rear "andside portions of the mechanism with only a few bonding fixtures secured to the mechanism conveyor Chain Fllghfe is "an eievauoner the ldti' fei fiofit Side of Figure 2 illustrating the action of the suee'e'ssive bonding iixtures'as't hey open to damp the shoe and lining assemblies; ei'tainoft he fixtures having parts removed therefromior purposes or clarity; I I

Figure 5 is a partial front elevation of Figure 2 showing the success-ion ofbohdi'ng fixtures and the two clai'nping devices f Iii-"the bonding fixtures "Figure 6' is a irontelevationofone set of bonding fixtures hailing shoe and lining assemblies clamped therein;

Figure? is a top view 'of'twosets"ofhonding fixtures-With eertaiz'rparts thereof "being Broken away and eertain parts setidnd;

Figure 8 is a fragment" of} Figure 2 snowing the eonfi'g'urat'ion or the Gain rail'wl'iichoontrol's the clamping aetion of-the bondihgfixtllres';

Figure 9 isa side eli'iatioh sifi'iilai' 50 1 52111? *8 si'iowingeertainparts'of the complete mechainsm in diagram;

Figure 10 'is a'si'de elevation or-onepower 1 m. clamping device as it acts on'a bonding fixture;

Figure 11 is 'a "bottom view of the device of Figure 10;

Figu're l2 is'a topviewofthe deride ofii -ismsi0 with various partsbeing broken awa for clarity Figuremf is a'part'iallongitudinalseotion of the reaction or lower jaw "asseniloly of the device of Figure ll);

"Figure 14 is a section of the lowr'jaw assembly taken substantially "on "section line l4 l 4 of Figure 1.3;

Figure 15 is a longitudinal section of thepressure or upper jaw assembly-of the-device of Figure 10;

Figure 16 isasectional view of'the underside of the upper iaw assemb'ly as it is pos'iti'oned in Figure 10;

Figure 17 is a'iragmental view" of one-power clamping device as it acts on a' bonding fixture;

Figure 181s an end view of two bonding fixtures "rigors"r9 is aside elevation 6r thfliiibie Band Figure 21 is a diagrammatic illustration of the bonding apparatus control system; and

Figure 22 is a section taken on section line 2222 of Figure 20.

General description floor space, ordinarily occupied by prior art de-.

vices, for other machinery.

The apparatus generally comprises a heating oven 38 which may project some twenty or thirty feet above the roof of a two story building in which the apparatus may be housed, and a conveyor 32 preferably of the chain and sprocket type which includes a sprocket assembly 34 journaled in the top portion of oven 36 and two lower sprocket assemblies 36 and 38 which are disposed equidistant from and adjacent to the building floor. The operator of the apparatus stands facing the front sprocket assembly 38 (see Figure 1) and performs his duties as hereafter will become apparent.

As previously explained, in bonding lining to a brake shoe, it is advisable to clamp the shoes and linings together with a predetermined pressure before heating. A bonding fixture 46 (see Figure 6) is used for this purpose, and as viewed in Figures 1 to 3 and 5, a succession of these fixtures are secured to conveyor 32 so as to provide an endless chain of fixtures. These fixtures 40 are so arranged that as they are transported along, they will automatically open and close at predetermined locations; e. g. the fixtures will be open when they are directly in front of the operator who merely loads them with shoe and lining assemblies, will close thereafter and remain closed until having passed completely through the oven 30 and have reached the horizontal portion of conveyor 32 between sprockets 36 and 38 where they will open to discharge the bonded shoe and lining assemblies.

The complete apparatus is suitably supported by a vertical frame structure 42, comprised of four upright corner posts, which carries the various sprocket assemblies 34, 36, and 38 and other parts and devices to be hereafter described. As will be seen more clearly in Figures 2, 3, and 8, an auxiliary frame is supported by frame 42 and has a front section 44 inclined at approximately degrees with the horizontal, a vertical rear section 46, and a horizontal bottom section 48. Actually, this auxiliary frame determines the path of the conveyor 32 and is provided with conveyor tracks 50 (Figure 8) which receive and guide the chains of conveyor 32.

In order to simplify the description, the mechanism parts or assemblies will now be individually described in detail with an explanation following of the manner of their association with the other mechanism parts.

Portable brake shoe assembly holding device- Bonding fixture Reference is now made to the bonding fixtures 48' of Figures 4, 6, and 7, Figure 6 illustrating the manner of securing two fixtures in end-toend relation to obtain a single fixture set or assembly 52 which is adapted to handle two separate brake shoe and lining assemblies simultaneously. Each fixture 40 comprises a support or C-shaped frame 54 having a bar member or beam 56 pivoted on the outer end 58 thereof. This beam 56 may be pivoted to open as illustrated in Figure 4 and is provided on its pivoted end with a cam follower arm and roller combination 68 which is engaged by a cam rail to be more fully described hereinafter. The inner end of the beam 56 is formed with a tooth 62 which is engaged by a pivoted latch 64 to lock the beam 56 in its illustrated position. To unlock beam 56, the latch 64 is merely pivoted out of engagement with tooth 62. The adjacent ends of two frames 54 are bolted together as at 66 and have their outer ends suitably secured to the chains 68 and T0 of conveyor 32. It has been deemed preferable to combine in side-by-side relation, two fixture assemblies 52, as viewed in Figure '7, in assembling the fixtures to the conveyor 32, making the endless chain of fixtures 40 consist of successive pairs of fixture assemblies 52. The purpose of this manner of combining fixture assemblies 52 will become apparent hereafter.

Each fixture 40 is provided with a clamping band or backing 12 which is preferably constructed of a strip of flexible spring steel having a width slightly larger than that of a brake lining to be bonded. Apertured fittings or hinge links 14, secured to the ends of this band I2, are received on respective pins 16 supported in parallel spaced relation with the inner surface of the frame 54 by means of pairs of spaced linkage plates 18. These plates 18 are removably secured to the end portions of frame 54 by means of bolts 86. Thus it is observed that eachband I2 is cradled in the concave portion of its frame 54 in spaced relation therewith, the amount of spacing being determined by the size of the plates 18 and the spacing of pins 16 from the concave surface of frame 54. It should be understood that this band 12 serves as a backing or reaction member against which a brake shoe and lining assembly may be clamped. Since the band 12 is flexible, it will readily conform to the convex curvature of the brake shoe assembly and serve to equalize the clamping pressure along its entire length; hence, this band 12 may be characterized as an equalizer.

The clamping mechanism of each fixture 46 comprises a pressure member or clamp 82 which consists of a pair of convexly shaped plates spaced apart to straddle a brake shoe web and rigidly fastened together in any suitable manner. The clamp 82 is universally swivelled at 84 to one end of a pin 86 which is reciprocably received in a transverse opening 88 in the central portion of clamping lever or beam 56. The pin 86 and opening 88 are preferably splined to prevent relative rotation, and the end 96 of pin 66 is provided with nuts 92 to retain the pin 86 in assembled position.

The clamp 82 and beam 56 are normally forced apart by a pair of relatively strong springs 94 fitted into sockets 95 in beam 56 on opposite sides of opening 88 to bear against opposite ends of a yoke 96 which is centrally apertured to receive pin 36. An abutment nut 98 is received on the lower end of pin 86 to be engaged by the yoke 96. As viewed in Figure 6, the brake shoe assemblies are compressed against their respective backings 12 by means of the clamps 82 under the compressive force of the springs 94. It will be obvious-that-these springs 91 also-cooperate with the'respective l-atchesiM to retain beams "56 in their illustrated locked-positions. For-purposes of convenience in olaiming this.invention, the combination of beam :56, pin'86,-and springs.94 maybe characterized-asa pressure developing mechanism which carries pressure member 82.

The clampingpressure-onthe shoe assemblies, as desired for springs '-94, "found to be satisfactory, is approximatelyone hundred sixty pounds 160-) 7 per square inch-of lining area. I Other pressuresof course may be used; however, this pressure has produced more nearlythe desired bonding result. Inasmuch as this relatively high spring pressure is acting on the engaged latch 84 and tooth 'li2,a correspondingly'high pressure, acting in an opposite direction, is necessary-to break the engagement. Therefore, in or'der to facilitate latching and unlatching tooth Grand beam 56, the beam 55 and frame fl' are compressed together suflicientlyto spread apart the engaging surfaces of the latch and tooth 64, 62. When this break occurs, the'latch 64 maybe freely rocked out of latching position, and thereafter the beam 56 may be pivoted-out'of operative engagement with the-brake shoe assembly to accommodate the latters removal.

It should be mentioned here that-the universal swivel connection 84 between the clamp 82 and the pin 86 allows the clamp =82to rockto solidly engage the concave surface of the brake-shoerim without producing any-bending moments on pin 86 and to produce a uniform pressure along the lined-length of thebrake shoe rim. The combination of the band 12 and the rockable clamp 82 provides a reliable, uniform pressure clamping device which will not distort 'theshape of the brake shoe. Furthen'the shoe-engaging edge of clamp 82 maybe notched or undulated topermit the fiow of hot aircurrents therethrough for uniformly heating the brake shoe assembly.

A tension spring 00 is preferably connected between adjacent latchesfi4xtourgethem out of engagement with the respective teeth 62 when the beams aresufiiciently depressed.

To facilitate the latching and unlatchin'g'action of each'fixture it, a pair of parallel, oppositely disposed compression surfaces are provided, one surface being'forme'd on beam EB'near' tooth 52 and indicated'by reference numeral I02 'andithe other surface being similarly formed on the opposite side of frame 54 and beingindicated by reference numeral "54. By bringing the jaws of a clamp or vice against these surfaces 102 and Mid, the beam'56 may be pivoted'inwardly against the 'forces of the springs 94 to'break the engagement of latch 64.

A pair of spaced guide bars I06 are formed on the inner end of each frame 54 and serves to guide tooth 62 and latch 64 into engagement.

Operating cam for bonding fixture the beams 5 6 slowly inwardly lto 'clamping -posttion; this gradual swinging action'occurring during-the travel of the fixtures -40 'on conveyor 32. Once closed and latchedgthe fixtures lil eontinue their travels upwardly -through "the :oven '30, around sprocket assembly $4, and downwardly through oven-30. 1 Upon leaving. oven 3b, the fixtures are unlatched and immediately following this unlatching, the .ifixtures are again successively, r gradually :acted 1 upon to open zthem, this opening :action be'ginning :J'u'St ;prior to -.their rounding rear sprocket assembly -36 \(see sliigure 9). Then, in traversing the distance between sprocket assemblies 36 .and 38, the i fixtures .are inverted and are completely opened .(see l Figure 4), *the brake shoe assemblies merely falling, under the force of gravity, from :the fixtures. The fixtures now being open, .are ready for .reloading. "Thus it becomes apparent that 'rthe above+described function is :continuous with :the operator performing only the .isingle operation of loading the fixtures.

The mechanism .foroperating the beams 56 of fixtures 40 consists of a'length of snakelike cam rail, generally indicated by reference numeral Hi3 in'Figures 8 and- 9, which begins just above sprocket assembly 36, passesaround-sproeket assemblies 36 and "38, and ends a short distance above sprocket assembly 38. Two cam rails i 08 aroused with one-being suitably secured to the inner side of one auxiliary framesectiorr E4, 46, *liland theother being similarly'secured -to the other auxiliary frame section. These rails M8 run generally parallel to-adjacen't, respectiveconveyor chains 68 and I0 and conveyor chain tracks 59, but are peculiarly'shaped at certain locations as will be described later.

With the fixture assemblies52 suitably secured to chains 63 and 10, the cam followers thereof are arranged to engage the respectiverails Hi8. Hereafter, since the two rails 108 are formed to substantially the same shape, a description of one willsuflicefor both. 'That p'ortion of the rail 188 which passes around sprocket 36, generally ind-icated by the'letter B in Figures 8 and 9, runs substantially parallel to a respective one ofthe conveyor-chains 6B or 1-0,-and is so formed as to be engaged by the roller H0 offixture'fo'llower arm 60. The fixture 40 is'in closed but unlatched position as it traverses this portion Bend the solepurp'ose ofthis portion B is to engage-the top side of roller H0 (asviewed in'Figure 6) to hold beam 56 in such closedposition.

Next, the roller H0 rides in portion'C of :rail ")8 which is preferably channel-shaped; however, the-roller H0 engages only the side H'2'as viewed more clearly in Figure 4. This portion C is'shaped with a degree longitudinal twist to allow'th'e beam 56 to gradually drop open, 'or' fall aboutits pivot 58, so that by thetime the fixture iflreaches'the sprocket assembly 38, it will be completely'open'and have discharged-the brake shoe'assembly.

'The'portion of rail Ilia-from the end of portion C, around-sprocket assembly 38, and through distance A is substantially parallel to-the conveyor 32 :path' an'diis suitably formed to-retain rollerl I 9 in such'a positionaswillhold beam 56 completely open.

'Theportion D of rail I08 isprovided with a 180 or more degree longitudinal twist and -is 'in clined out :of parallel relation with "conveyor =3 2. ThisyportioniD i's'pre ferably formed fof a single flat section .of :steel'withthc surface 114 being engaged'hythefixture roller H0. "The pu pose of this twist is to pivot the follower arm 60 and the beam 56 about the axis 58 to closed position and prepare the fixture 40 for an immediately subsequent latching operation.

In order to prevent the beams 56 from slamming closed under the force of gravity as they operatively engage portions D, a pair of let-down cam rails II6 (see Figure are mounted on a frame support II8 (see Figure 2) and are arranged to be slidaoly engaged by the teeth 62 of beams 56 during the latters closing. These rails I I6 begin adjacent the-locations where the teeth 62 reach the upper crest of their swinging movement and terminate adjacent the path of the fixture latches 64. The sole purpose of these cam rails H6 is to provide gradual closure of beams 56, thereby preventing their damage should they be freely allowed to fall into'closed position under the force of gravity. Needless to say, these beams 56 are relatively heavy; thus the necessity for this cam rail structure H6.

Bonding fixture, latching and unlatching mechanismPower clamp In Figure 10 is illustrated a fixture-clamping device generally indicated by reference numeral I20, of which there are four, used to effect latching and unlatching of the various bonding fixtures 49 as they pass predetermined locations. The two front clamping devices I22 (see Figures 2 and 5) are supported opposite each other on the inclined portions 44 of the auxiliary frame, each device I22 straddling one row of fixtures 40, as illustrated in Figures 5 and 1'1, to automatically latch them.

The two rear clamps I24 are also supported opposite each other on the vertical, auxiliary frame portions 46, each of these devices I24 likewise straddling a row of fixtures 40, as illustrated in Figure 10, to automatically unlatch them. Th front power clamps I22 are supported adjacent the trail end I26 of cam rail I08, while the clamps I24 are supported adjacent the head or entry end I28 of cam rail I08. Hence, the arrangement operates to latch the fixtures 40 immediately after they leave cam rail end I26 and to unlatch them just following their engagement with cam rail end I28.

Since the four clamping devices I22 and I24 are substantially identical, a description of one will suffice for all except in the details of difference which will be specifically described.

Referring now to-Figure 10 which illustrates the power clamp I24 used on the rear of the present invention as shown in Figure 3, the C-shaped clamp frame I30 is carried by an auxiliary frame member 46. The shape of this frame I30 is formed by two spaced sides I32 and I34 interconnected by means of a rigid, preferably integral, side I36. As illustrated more clearly in Figure 11, frame I30 is made of two C-shaped side sections I38 and I40 which are rigidly secured together by means of spaced, weldedsupporting plates I42 and I44 (shown in dotted lines in Figure 10) and a plurality of bolts I46 and I48. A plate I50 is hinged to frame member 46 about a pivot I52, and extends between the two sections I38 and i401. This plate I50 is pivotally connected to plat I42 by means of a pin I54 (shown in dotted lines) ,the axis of which lies in a plane normal to the axis of hinge pivot I52. Thus it is seen that the clamp frame I30 may be tilted or rocked about pivot I52 inthe general plan of the frame I30 or may be laterally swung about the pin I54.

A plate-like extension or supporting-memberportion I53 is suitably rigidly secured to the hottom portion of frame or rigid-supporting member 46, as viewed in Figure 10, to also project between the C-shaped side sections I38 and I40. Another pivot pin I58 having an axis collinear with the axis of pin I54 is suitably secured to this extension I56 to depend therefrom through an elongated opening I60 in the lower connecting plate I44. The width of this opening I60 is coextensive with the diameter of pin I58 while the length is in a direction to permit a limited tilt of frame I30 about hinge pivot I52. Journaled on pin I58 immediately below plate I44 is a grooved roller I62 which is engaged on one peripheral side by a tension spring I64 (see Figure 11) connected at one end I66 to frame section I38 and at the other end I68 to an anchoring block I10 suitably secured to depend from extension I56. This spring I64 functions to swivel frame I30 to released position against a stop I12 (see Figure 11) secured to the edge of extension I56 and serves to yieldably retain the clamping device I20 in released position.

- The lower side I34 of frame I30 carries a reaction or lower jaw assembly I14 which is illustrated in detail in Figures 13 and 14. This assembly I14 comprises essentially two parts; a retainer block I16 provided with a socket I82, and a T- shaped support block or lower jaw I18 (see Figure 18) the stem I80 of which is rotatably received in socket I82. A thrust bearing I84 is preferably interposed between the bottom of socket I82 and the end of stem I80, and needle bearings I86 between the sides of socket I82 and the stem I80.

Support block I18 is retained on block I16 by means of a pair of arcuate plates I 88 partially surrounding stem I to provide diametrically opposit spaces I90 which receive th opposite ends 01 a pin I92 transversely secured through the center of stem I80. Thus the swivelling movement of support block I18 is limited by the engagement of pin I92 with the ends of the plates I88. As viewed in Figure 10, a tension spring I94 is connected between one end of pin I92 and side I34 of frame I30 thereby yieldably rotating lower jaw I18 to its stopped position as illustrated in Figure 14.

Referring now more particularly to Figures 0, 15, 16 and 18, the pressure or upper jaw assembly I96 is constructed quite similarly to lower assembly I14. It comprises a pressure-trans mitting-member or bar I90 provided on one end with a clevis 200 and in its other end with a longitudinal socket 202 which pivotally receives a stem 204 of T-shaped clamp member or jaw 206. Thrust bearings 208 and needle bearings 2 I0 are used to rotatably support stem 204 in the socket 202. A pair of locking membersv 2I2, similar to the plates I88 of Figure 14, are secured to the socket end of bar I98 and are formed with arcuate cutout portions 214 which engage the annular shoulder 2I6 on stem 204 to retain the latter in place. Similarly to the lower jaw assembly I14, 2. pin 2 I8 is secured to stem 204 to lie in the spaces 220 formed between the stop members 2I2. The cooperative function of these stop members 2I2 and the pin. 2I8 is the same as the similar parts of the lower jaw assembly I14. In order to yieldably retain jaw 205- in the pivoted position illustrated in Figure 16, a spring 222 is compressed between one end of pin 2I8 and an extension 224 formed on one of the two step members 2 I2.

Referring to Figures 10, and 18, it is seen that the jaw 206 of the upper jaw assembly I96 and the jaw I18 of the lower jaw assembly I14 are juxtaposed in cooperative relation to engage the surfaces I02 and I85, respectively, otfixturesA-O. This upper jaw assembly I95, is supported by means of a lever 226- which is connected at one end to the clevis 2851 of bar I98 and at the other end of a pneumatic power cylinder 228. This lever 22% is pivoted intermediate its endsto the end of side I32 at 235 whereby reciprocatory movement of the pistonoi power cylinder 228 will cause lever to rock aboutpivot 230," and to raise and lower jaw assembly I815 accordingly.

In order to limit the. motion of: upper jaw assembly I93 substantially in line'with thedongitudinal dimension ofithe. bar I98, alinkage 232 is pivotally connectedb'etween frame side I32 and the lower portion of bar I98. Thusany'movement of jaw assembly I95 is substantially parallel to or'in line with the length dimension'of bar I98.

It is now obvious that Toy-moving; the powercylinder end of lever 225', thebonding fixture 41) may be clamped betwern jaws I-'I8- andx206 to depress the beam 55 to latch'or unlatchit as previously explained.

The power clamp I24, as shown in Figures 10, and 18, is used to unlatch the fixtures 4!); This unlatching action is facilitated by use of the -fingers 23% pivoted intermediate their ends to extensions-on linkages 23-2 The'upper endsof fingers 23 i-are connected to bar I98v by means of tension springs 236 which tendto. rotate these fingers 234- in: a counterclockwise direction;

A pair of latchedfixtures-W, as illustratedin Figure- 1o,- are acted. upon by this powerclamp 22th; the following manner. Asthe fixtures-40 passbetween the spreadjaws I73 and 208, the

power cylinder. 228 is energized to rock lever 226v ina'clockwise direction Thejaws I18 and 206 are brought into engagement with the fixture surfaces IM and IE2, respectively, and simultaneously, the lower-taperedend of each finger 234 engages the inner inclined side ofthe respective fixture latch l t.- The combination of the..power.cylinder 22.8 and lever 22 6.is suihciently powerful to compress the surfaces I02 and I 04 toward one another against the action of. springs 94 whereupon the engagement between the teeth. 62' on beams 56 and the latchesfie arebroken allowing the. springs 235' and fingers 234 to pivot the latchest l clockwise out of engagement with the teeth 52. Power cylinder 228 is now oppositely energized, and the jaws I18. and 206 thereby separated to. allow the fixtures 40 to continue on their. course. The actuation of the .power cylinder 228 is automatic and a system for controlling its actuation will be described hereinafter.

Referring now to Figures 2, 5, and 17,. the power. or latching clamp 22 is illustrated as being provided with a. latching mechanism generally indicated by the reference numeral 233. This mechanism 238 is comprised of 'an'elongated cam 24!} which is pivotally connected to the upper jaw assembly bar I98 by means of a linkage 24 2'; This cam 2.401s provided; at its lower end with a longitudinal'slot 24d arrange'dto receive a projection 2&5 extending laterally from the end of motion-stabilizing linkage 232'. A tension'spring 24' is'connected'b'etween the upper end of bar 240 and the projection 245'wlr'ereby the cam24fi' is yieldably urged downwardly.

Assuming th'at'the latch GZIis disengagedfrom tooth 62, as. illustrated by the dotted lines of latch 54, power cylinder 22B is actuatedto compress. thefixture surfaces 102 and are together. With. adownwardmovement of the upper jaw assembly I 96, spring 247, in thelatch'ing mechanism 238,: draws the camw240 downwardly until cam surface 248engages the outer side of" latch 84. Once the fixture: surfaces I02 and IM-have been pressed-sufficiently closetogethe'r; latch 55 will be rotated-counterclockwise 'bythe actionof spring 24'I andcam-surface Zed-until the latch overlies the'upper surface of tooth 62'. Thejaws of the power clampl2-2- arenow released a1- lowing the beam .56V to pivot outwardly under the pressure of springs 94 untilthetooth saengages and frictionally' lockswith latch 6 Figure 18 is a front elevation ofthe power clamp 524 as it. engages two successivebonding fixtures 45. Inasmuch as-two fixtures 4%. maybe acted upon simultaneously, it-is desirable to secure two bonding fixture assemblies 52 together as-shown in Figure 7.

Control mechanism Referring now to Figures 3, .8, and 21, the actuating system for the power clamps I22 and I24 will now be described. Air valve-aotuatingmechanisms are indicated. generally by reference numerals 25B and are-carried between the-sprocket assemblies 36 and 38 by the horizontalframe section 4% of the auxiliary, frame. There are two mechanisms 250 carried by. each ofthe. two frame sections 48, onemechanism. controlling the operation of. one power clamp-,.such as I22, and the other controllingra. power clamp-I 24. In asmuch as the mechanisms-250 are-identica-L-a description of one will suffice for all.-

A pivot shaft 252 is journaled in framesection 48. and is secured. on -one. end to atrip arm 254 which lies parallel and adjacent tolthe conveyor rail A cam.plate-:256. is secured on the end of arm 254 and is positioned to be engaged by thecam studs 258 "(Figure 6) on bonding fixture assemblies 52. It should be'note'd that these cam studs258 are=secured on the hi:- ture frames 54 immediately adjacent-the conveyor chains 63 and I0, andthereb'ytravel along a predetermined path parallel to the-conveyor chain guides 59* (Figure 8"). Thetri'p' arm 254 positions cam'plate'25t inthepath of'studs 2'58 whereby the shaft 252'wi1l be rockedeachtime a stud rides against" plate 256. On the other end of shaft 252 is secured a valve-a'ctuating arm 250 which momentarily opens normally closed air valve 262.

Referring now more particularly to- Figures 11 and 21, the power clamp I24" is operated in the following manner. The studs 258' arespaced along the" conveyor'chains' 68 and I0 a predetermined distance apart'so' that as one stud 258 engages a valve actuating" mechanism 250') the corresponding valve 262 will open allowing communication'of air pressurefrom sourcepipe 254 to master control valve 266 which routes'this pressure through conduit'258'to power cylinder 228. The piston in power cylinder 228-is"thereby forced outwardly to operatepowerclamp I24 and to clamp-a pair of'fixtures' lfl as explained previously. The cam studs 2'58are spacedto synchronize the actuation o'f power clamp I24-with the passing of a pair of fixturesbetween the power clamp jaws I18 and 2051' The power clamp I24 is normally'pivoted'against itsstop I12 (see Figure 11) by spring I64, and'themomentthis clamp I24 grasps a pair of'fixtures' 40, the jaws I It and 286 are necessarily carried along with the fixtures. This pivots'clamp' I24 about pins I54and' I53 and jaws I18 and-2Il6 pivot in'their respective sockets !82- and 202 (see Figures- 13 and'lfi);

Inasmuch as it is necessary. for clamp I24 to by the ear portions 282.

11 remain engaged with the fixture 48 only long enough for them to be unlatched, a valve is ar ranged to be actuated after a certain pivotal movement of the clamp I24 to release the fixtures 48 and allow the pivotal return of clamp I24 against its stop I12 by spring I64. Thus, the clamp I24 is readied for another fixture-engaging action. This releasing valve is indicated by reference numeral 218 and is preferably secured to extension I56 of vertical frame section 46. As clamp I24 rotates in a clockwise direction, as viewed in Figure 11, concomitant with the travel of the clamped fixtures 40, it eventually engages and operates valve 210 which is opened (see Figure 21) to send air pressure to master control itself for each pair of fixtures 48 which passes' between the power clamp jaws, and the four power clamps I22 and I24 are individually operated as predetermined by the spacing of cam studs 258 and the locations of the four valve actuating mechanisms 25!]. With this particular control system, it is obvious that a single mechanism 258 in combination with one master air valve 266 serves only one power clamp 122, or I24.

The bonding fixture clamping band The clamping band 12 in Figure 6 is more clearly illustrated in Figures 19 and 20. This band 12 consists of two parts, the first being a master band 214 and the second a locator band, 216 which is removably secured to one surface of master band 214. Master band 214 is preferably formed of a strip of flexible spring'steel having relatively high tensile strength and is provided on its ends with hinge plates 14 adapted to receive through the openings 218 thereof the' respective pins 16.

The locator band 216 is preferably a stamping formed to an arcuate shape and with a plurality of longitudinally spaced ears 288 on the longitudinal edges thereof. As viewed in Figure 22,

each ear 288 is bent to provide stepped portions 282 and 284, portion 282 being offset outwardly from portion 284.- The length of portion 284 is formed coextensive with the normal thickness of a brake lining segment 286 and the distance across the band between these portions 284 of opposite ears 288 is made equal to the normal width of the lining segment 286. Thus the liningsegment may be laterally positioned with respect to band 216. The rim 288 of a T-section brake shoe is similarly laterally positioned The lining 286 is longitudinally positioned by means of an abutment 290 on one end of band 216 while the corresponding end of the brake shoe rim 288 is likewise placed against a similar abutment 292 thus completing the operation of locating the lining segment 286 with respect to shoe rim 288.

The locator band 216 has one end formed to fit in a transverse slot 294 in one hinge plate 14, and its otherend engaged by the head of a cam screw 286 fitted to the other hinge plate 14. The head of screw 296 is formed with one flat from its illustrated position, the engagement Thus when these jaws IIB 12 with the end of band 216 will be freed thereby allowing the latter bands ready removal.

Operation The foregoing description of the embodiment of the present invention has included the operation thereof; however, a brief review of this operation will now be given.

The arrow F in the various figures (see Figure 2) indicates the direction of travel of conveyor 32. As the fixture assemblies 52 round sprocket assembly 38 and pass in front of the operator (see Figure l), the fixtures are open and ready for loading. The operator first positions a lining segment, such as the one 286 of Figure 22, on the clamping band 12 and then a brake shoe on top of the segment. Thereafter the operations of this invention are automatic with the loaded fixtures being first closed by the surface II4 of cam rail I88 (see Figure 8) and then latched by power clamps I22. The brake shoe and lining assemblies in the latched fixtures 40 are now compressed together under pressure and are transported upwardly and then downwardly through oven 38. Immediately upon leaving the oven, the fixtures are unlatched by power clamps I24 (an unlatching power clamp is illustrated in Figure 10), and thereafter operatively engage the cam rails I08 which cause the fixtures to swing open as they pass inverted between lower sprocket assemblies 36 and 38 to dump the brake shoe assemblies. The fixtures, now being open, are ready to accept other brake shoe assemblies.

Although only one embodiment of the invention has been illustrated and described, various changes in the form and relative arrangements of the parts may be made to suit requirements.

We claim:

1. A portable brake shoe assembly holding device comprising a frame, a flexible nonextensible backing carried by said frame, a pressure mem ber cooperatively associated with said backing to clamp therebetween a shoe and lining assembly, a lever fulcrumed on said frame having a portion between its ends formed to slidably receive a connecting pin which is secured at one end to said pressure member, a resilient means associated with said pin acting to spread said pressure member and said lever apart, said lever being operable to shift said pressure member into and out of clamping position, and a latch pivoted on said frame and cooperating with said lever to hold the latch in clamping position against the force of said force creatingmeans.

2. A portable brake shoe assembly holding device comprising a frame, a flexible nonextensible backing carried by said frame, a pressure member cooperatively associated with said backing to. clamp therebetween a shoe and lining assembly, a lever fulcrumed on said frame having a portion between its ends formed to slidably receive a connecting pin which is pivotally secured at one end to said pressure member, a resilient device associated with said pin acting to spread said pressure member and said lever apart, said lever being operable to shift said pressure member into and out of clamping position, and a latch pivoted on said frame and cooperating with said lever to hold the latter in clamping position against the force of said force creating means.

3. A portable brake shoe assembly holding device comprising a frame. a flexible nonextensible band supported between spaced portions of said frame, a pressure member having an engaging surface adapted to engage a shoe and lining as- 

